Rockville Centre, NY water hardness

Tap water hardness
39mg/L
2.3gpg
SoftReports range 26–39

Reported by Hempstead (village) · October 2025

NY typical
31 mg/L
EPA health violations since 2016
0
Data
Utility report

Tap water in Rockville Centre has about 39 mg/L of hardness, which is 2.3 grains per gallon. On the USGS scale that counts as soft. The number comes from Hempstead (village), dated October 2025. Reports for this system disagree, with values from 26 to 39 mg/L.

Rockville Centre on the hardness scale, with nearby cities
060120180240300360+NY typical 31Lynbrook: 32 mg/LLynbrook 32Freeport: 33 mg/LFreeport 33Roosevelt: 33 mg/LRoosevelt 33Lakeview: 39 mg/LLakeview 39Baldwin: 42 mg/LBaldwin 42Oceanside: 42 mg/LOceanside 42West Hempstead: 48 mg/LWest Hempstead 48Franklin Square: 48 mg/LFranklin Square 48Malverne: 51 mg/LMalverne 51Hempstead: 53 mg/LHempstead 53Rockville Centre 39mg/L as calcium carbonate060120180240300360+NY 31Lynbrook: 32 mg/LLynbrook 32Lakeview: 39 mg/LLakeview 39Baldwin: 42 mg/LBaldwin 42Oceanside: 42 mg/LOceanside 42West Hempstead: 48 mg/LWest Hemps. 48Malverne: 51 mg/LMalverne 5139 mg/Lmg/L as calcium carbonate
Soft 0–60 mg/LModerately hard 61–120 mg/LHard 121–180 mg/LVery hard 181+ mg/L

At 39 mg/L, Rockville Centre is close to the typical New York figure of 31 mg/L. Of the 10 nearest cities we track, 3 have softer water and 6 have harder. The range nearby runs from 32 mg/L in Lynbrook to 53 in Hempstead.

What 39 mg/L means at home

Soap and shampoo lather with very little product. Kettles and showerheads stay mostly free of white crust.

Some people notice that soap feels slow to rinse off in soft water. That slippery feel is normal and harmless.

Hardness is not a health problem, and EPA sets no limit for it. It is a matter of scale and soap.

What to do about it

Nothing, as far as hardness goes. At 39 mg/L a softener would have almost nothing to remove.

Carbon filter

If the water tastes of chlorine, a pitcher or faucet carbon filter takes care of that. It does not change hardness.

EPA record for Rockville Centre's water system

Hempstead (village) · PWSID NY2902827

No health-based violations since 2016

Serves about 56,000 people from groundwater.

Health-based
0
Monitoring or reporting
2
Open now
0

TapWaterData ties Rockville Centre to this system. EPA's service-area records do not name Rockville Centre, so check the utility printed on your water bill.

Health-based means a contaminant above its legal limit or a missed treatment step. Monitoring and reporting violations are late or missing tests and notices. Source: EPA ECHO, 2026Q3 export, violations with periods starting 2016 or later. Full EPA record.

Questions

Is Rockville Centre water hard?

No. It measures about 39 mg/L (2.3 grains per gallon), which the USGS classes as soft.

What is the water hardness in Rockville Centre in grains per gallon?

About 2.3 gpg. One grain per gallon equals 17.1 mg/L, so 39 mg/L divided by 17.1 gives 2.3.

Has the Rockville Centre water system had EPA violations?

EPA records show no health-based violations for Hempstead (village) since 2016. There were also 2 monitoring or reporting violations, which are about late or missing tests and notices.

Nearby cities

All 149 cities in New York

Hardness data: TapWaterData US Water Hardness (utility report, October 21, 2025), CC BY 4.0. Population: US Census Bureau. Violations: EPA ECHO. How we use them.